Bolt and charge operated tool for driving in a bolt



y 966 H. BEHREND ETAL 3,249,279

BOLT AND CHARGE OPERATED TOOL FOR DRIVING IN A BOLT Filed Dec. 16, 1963United States Patent.

4 Claims. (Cl. 227-) This invention relates to bolts for bolt driving orramming tools having a barrel-type housing containing a pisvton having arod or ram portion and actuated by a charge, such as an explosivecharge. The piston or ram drives the bolt from the barrel of the toolinto an opposed or counter surface, such as a panel or wall. Thisinvention relates also to a tool for driving in such bolts.

The tools of this type which have a bolt driving piston member have theadvantage in comparison with similar tools which project the bolt fromthe barrel that the handling of these piston operated tools is lessdangerous and that they may be applied more suitably for driving boltsor nails into a surface or a material which is less resistant. They maybe adjusted to operate through a limited stroke length or strikingdistance of the piston whereby the ramming depth for the bolt is alsolimited or adjusted.

It is a feature of the invention to provide a bolt which is particularlyadapted for this type. of bolt driving tools, especially for use withthe piston operated tool disclosed herein. Various modifications of thehead portion of the associated bolt are disclosed herein. The bolt maybe driven into a panel or wall or the like although neither the bolt northe tool has a special arrangement or elements for guiding the boltwhile it is driven out of the barrel into the opposed surface. It istherefore also a feature of the invention to provide a bolt driving toolof the type described above which is especially suited for working witha bolt according to the invention.

It is a further feature of the invention to provide a device by means ofwhich the bolt may be easily inserted and lodged in the tool barrel inengagement with the piston.

It is another feature of the invention to provide a retaining elementwhich is applied to the end of the bolt facing the piston or the headend of the bolt. The retaining element permits a clamping or wedginginsertion into a front end recess of the piston. After being 'thussecured to the piston the bolt extends freely along the axis of thebarrel and requires no special guiding means inside the barrel. The boltis easy to manufacture and the bolt driving tool may also be producedeasily and inexpensively because it no longer requires a barrelcontaining means for guiding the bolt.

The clamping element or retaining body of the bolt may have a number ofdifferent forms. For this purpose the outer end of the piston is merelyprovided with a V recess or -opening for receiving a retaining element.

Another'feature of the invention is the provision of a loading rod forintroducing and lodging the bolt with its retaining member in the frontrecess or opening of the piston and consists of a guide tube or loadingtube having a bore for receiving the bolt shaft with a front portion orprojection adapted to bear against the end of the bolt which carries theretaining member or against the retaining member itself, the diameter ofthis projection being smaller than the diameter or opening of the recessin the piston which receives the head end of the bolt.

In the tool disclosed herein, which is particularly designed to drive inthe bolts of this invention, the piston is divided into a piston sleevewhich receives the adjacent end or the head end of the bolt, 8. ram orpiston rod por- "ice tion projecting forwardly of the piston head andadapted to enter the piston sleeve bore, a part which lies rearwardly ofthe piston head on the side adjacent the drive chamber, and an elasticbuffer member arranged between the piston sleeve and the piston head andsurrounding the piston rod-portion. The elastic bulfer reduces theimpact or shock of the piston during the injection of the bolt thuscausing less damage to work materials such as strips and boards whichare to be connected to a wall by means of thebolts. While driving in thebolt, the piston rod pushes the bolt head from the opening in the pistonsleeve.

It may be desirable to provide in the barrel containing the piston atensioning member which bears resiliently against the piston sleeve orpiston head and disposed axially of the barrel in the manner of atensioning rail or plate. Such a tensioning member allows an adjustmentof the impact force or stroke of the piston as this member, which bearsradially against the piston sleeve or the piston head, makes it possibleto set the piston at different intervals or distances from the drivingchamber.

Additional features and advantages of the invention will appear from thefollowing description in combination with the accompanying drawingswhich illustrate for the purpose of examples various embodimentsincluding the elements which are necessary to a full understanding ofthe invention.

FIGURE 1 shows a longitudinal section through the front portion of acharge operated tool according to the invention with a bolt set into thepiston sleeve.

FIGURE 2 is a longitudinal section through the tool according to FIGURE1 after discharge of the tool and insertion of the bolt.

FIGURE 3 shows a longitudinal section of the loading tube for settingthe bolt in the barrel.

FIGURE 4 shows a bolt with an enlarged threade head.

FIGURE 5 shows a part of the threaded bolt head of FIGURE 4 in anenlarged view.

FIGURE 6 shows a bolt with a threaded head whose diameter is smallerthan the diameter of the piston rod.

FIGURE 7 is a side view, partly in longitudinal section, of the end ofthe piston rod with an inserted bolt of modified form.

FIGURE 8 is a section similar to FIGURE 7 showing a bolt with a rivettype head.

FIGURE 9 shows a section similar to FIGURE 8 with a bolt having aconical retaining ring around the bolt shaft.

FIGURE 10 shows a section similar to FIGURE 7 in which the bolt head hasa conical retaining member axially at the outer end.

FIGURE 11 shows a partial section similar to FIG ER? 10 in which thebolt has a retaining flange below the FIGURE 12 is a partial sectionsimilar to FIGURE ll with a retaining member in the form of a wire ringsurrounding the bolt shaft.

The bolt driving tool of the invention illustrated generally in FIGURESl and 2 comprises a housing 1 in the form of a barrel in which a piston2 is received for reciprocation and adapted to be driven forward in thebarrel by igniting a charge indicated by numeral 17 placed in a firingchamber at the rear end of the barrel in order to drive the bolt 3 intoa wall or the like. A piston sleeve 4 is provided in the front end ofthe barrel to receive the bolt head. The piston 2 has a ram portion 5which is received centrally in-the opening or bore of the piston sleeve.Between this sleeve 4 and the piston 2 a buffer member 6 is arranged,which is made of an elastic material as shown in the embodimentillustrated in the drawing. The buffer has such a form, preferablyincluding an intermediate diametrically reduced portion, that it may becompressed axially between the piston 2 and piston sleeve 4.

A 'tensioning member 7 inserted into the side of the barrel bearsagainst the piston sleeve 4 due to a spring 8 which presses it inwardly.The tensioning member 7 provides that the piston 2 may be inserted to agreater or smaller degree into the driving chamber 18 without slidingout of the barrel. Rearwardly of the piston head is the driving portionof the piston which is received in the driving chamber.

In the embodiment of FIGURE 1 the shaft of the bolt is provided at theend below the head 9 with a retaining or clamping element 10 of elasticmaterial by means of which the bolt is'set into the bore of the pistonsleeve so that the bolt extends freely axially of the barrel away fromthe piston sleeve. 7

The bolt shown in FIGURE 4 has a threaded head 11.

Into the threads of this threaded head portion a wire spiral 12 isplaced and extends with its outer diameter slightly beyond the outerdiameter of the threads as shown in FIGURE 5. Before inserting the bolthead into the piston sleeve the wire spiral is preferably not in contactwith the sides of the threads.

FIGURE 6 shows a bolt which has a smaller shaft diameter than the boreof the sleeve or of the piston rod and no head. The end of the boltadjacent the sleeve has a threaded portion. On this end an elasticretaining of clamping member 13 is placed before setting it into the sle n n For the purpose of setting the bolt into the piston sleeve- In theembodiments of FIGURES 7-12 the .bolt is set directly into the forwardend of the piston rod whose end facing the bolt has a recess 19 for thispurpose.

In the embodiments of FIGURES 7, 10, 11 and. 12 the bolt is providedwith a threaded head 11 while in the examples of FIGURES 8 and 9 it hasa cylindrical nailtype head 11.

According to FIGURES 7-9 a metal clamping .ring 20 is disposed on thebolt shaft in the vicinity of the bolt head, this ring being made forexample of brass. The bolt may be furnished with the clamping ring butit is possible that the clamping ring be furnished separately so that ithas to be placed on the bolt shaft before using the bolt. The clampingring may also be in the form of a split ring.

InFIGURES 7 and 8 the opening of the bore which receives the bolt headmay be of a conical form diverging inwardly toward the axis and theconical surface is in dicated by numeral 21.

In the embodiment of FIGURE 9 the outer circumference of the clampingring is conical. The conical outer circumference is indicated by numeral21. It should be understood that the opening of the bore receiving thebolt head and the clamping ring may be formed conically so as tocomplement each. other.

FIGURE 10 shows a bolt whose head 11 has a conical axial extension 22and the bottom of the recess 19 in the end of'the piston rod is providedwith a corresponding conical recess 23.

The bolt shown in FIGURE. 11 is provided with an annular clampingflange20. The receiving opening in the front part19' is formed conically. Inthis embodiment the .peripheral surface of the flange and the receivingopening of the piston may be conical. Similarly the peripheral surfaceof the flange alone may be conical.

According to FIGURE 12 a clamping ring 20" of wire may be arranged onthe bolt shaft, by means of which the bolt is clamped securely in therecess 19 which has a part a plastic material.

21 which diverges conically outwardly. The clamping ring or wire ring20" may be of any suitable material, such as copper, brass, iron or thelike. It is also possible to make the wire ring or the annular retainingmember of The end of the wire which forms the ring or annular retainingmember need not be connected, and may have a desired cross-section suchas round, oval, rectangular, square or the like.

In each of the embodiments the size of the angle of the conical surfaceis so chosen that it provides an automatic clamping action.

A guiding or loading tube as illustrated in FIGURE 3 may also beemployed for inserting the bolt of FIG- URES 7-ll into the piston.

What is claimed is:

1. A charge operated bolt' driving tool comprising in combination abarrel having a bore at one end for receiving and.

ejecting a headed bolt having a frictionally engaged retaining meansassociated therewith,

a firing chamber at the other end of said barrel for receiving a firingcharge, I

a driving chamber between said bore and said firing chamber andcommunicating therewith, and

a composite piston member received for reciprocation in said barrel andincluding (a) a piston head having a diameter slightly less than theinner diameter of said bore,

(b) a ram portion extending from said piston toward said one end of saidbarrel centrally of said bore, i

(c) a driving portion extending centrally from said piston head towardsaid other end of said barrel and received for reciprocation in saiddriving chamber,

(d) a substantially smooth walled axial recess in the end of said ramportion for receiving the head of said bolt and said retaining means.

2. The bolt driving tool according to claim 1 wherein said recess has anoutwardly diverging frusto-conical wall whose base diameter is less thanthe diameter of said retaining means.

3. A charge operated bolt driving tool comprising in combination abarrel having a bore at one end for receiving and ejecting a headedbolt, a firing chamber at the other end of said barrel for receiving afiring charge, a driving chamber between said bore and said firingchamber and communicating therewith, and a composite piston memberreceived for reciprocation in said barrel and including (a) a pistonhead having a diameter slightly less than the inner diameter of saidbore,

(b) a ram portion extending from said piston toward said one end of saidbarrel centrally of said bore and having a relatively small diameterleaving an annular space between itself and the inner surface of saidbore,

(c) an axial recess in the end of said ram portion for receiving thehead of said bolt,

(d) retaining means associated with said bolt head for engaging thewalls of said-recess to-fix said bolt on said ram portion coaxiallytherewith,

(e) a driving portion extending centrally from said piston head towardsaid other end of said barrel and received for reciprocation in saiddriving chamber,

(f) a piston sleeve slideably received on said ram portion at its outerend and reciprocating therewith, p

(g) a buffer means of resilient material disposed between said pistonhead and said piston sleeve and filling substantially said annular spacehetween said ram portion and the inner surface of said bore, and (h) acircumferentially reduced intermediate portion on said buffer meansallowing a limited axial compression of the resilient material of saidbulfer means under the bolt driving impact, said resilient materialmoving said piston head inwardly sufiiciently to separate said ramportion from the bolt head upon returning into its normal distendedposition. 4. The bolt driving tool according to claim 3 wherein saidbuffer means engages the outer surface of said ra/rn portion'at itsinner periphery and engages at its outer periphery the inner surface ofsaid bore at least at the ends.

References Cited by the Examiner UNITED STATES PATENTS 2,665,421 1/1954Temple 227-10 3,023,414 3/1962 Sinex 22710 3,050,732 8/1962 Termet 22710FOREIGN PATENTS 518,452 3/1953 Belgium.

GRANVILLE Y-. CUSTER, 111., Primary Examiner.

1. A CHARGE OPERATED BOLT DRIVING TOOL COMPRISING IN COMBINATION ABARREL HAVING A BORE AT ONE END FOR RECEIVING AND EJECTING A HEAD BOLTHAVING A FRICTIONALLY ENGAGED RETAINING MEANS ASSOCIATED THEREWITH, AFIRING CHAMBER AT THE OTHER END OF SAID BARREL FOR RECEIVING A FIRINGCHARGE, A DRIVING CHAMBER BETWEEN SAID BORE AND SAID FIRING CHAMBER ANDCOMMUNICATING THEREWITH, AND A COMPOSITE PISTON MEMBER RECEIVED FORRECIPROCATION IN SAID BARREL AND INCLUDING (A) A PISTON HEAD HAVING ADIAMETER SLIGHTLY LESS THAN THE INNER DIAMETER OF SAID BORE, (B) A RAMPORTION EXTENDING FROM SAID PISTON TOWARD SAID ONE END OF SAID BARRELCENTRALLY OF SAID BORE, (C) A DRIVING PORTION EXTENDING CENTRALLY FROMSAID PISTON HEAD TOWARD SAID OTHER END OF SAID BARREL AND RECEIVED FORRECIPROCATION IN SAID DRIVING CHAMBER, (D) A SUBSTANTIALLY SMOOTH WALLEDAXIAL RECESS IN THE END OF SAID RAM PORTION FOR RECEIVING THE HEAD OFSAID BOLT AND SAID RETAINING MEANS.